【作者】 夏云峰；

【导师】 薛鸿超； 李昌华；

【作者基本信息】 河海大学 ， 港口海岸及近海工程， 2002， 博士

【摘要】 本文采用非交错曲线网格二、三维水流泥沙数值模型研究感潮河道水流泥沙问题，主要内容有： (1)综述水流泥沙数值模型的发展概况，及其工程应用。 (2)从挟沙水流两相流运动方程导出三维挟沙水流运动方程，论述各种紊流模型。 (3)以Poission方程变换为基础，建立拟合曲线坐标系下非正交和正交曲线网格生成方法。 (4)二维水流泥沙数值模型，采用非交错网格布置，所有计算变量采用同一控制体。由Rhie和Chow动量插值思路导出控制体交界面流速公式。选取曲线坐标系下逆变速度通量分量为独立变量，由水位校正法求解水位流速耦合问题。二维悬沙和底沙运移采用不平衡输沙模式，分析输沙方程的源项处理以及非均匀沙分组挟沙能力和床沙级配调整。 (5)二维水流泥沙数值模型采用S型弯道水流运动计算验证，结果和实测资料基本吻合。西气东输过江工程，采用该模型模拟南京西坝～泗源沟河段不同流量水流运动，并计算一水文年过程该河段的河床冲淤变化，结果和实测资料也基本一致。 (6)非交错曲线网格三维水流泥沙数值模型，采用拟合曲线坐标和垂向σ坐标变换。水流运动方程压力项分解为静水压力和动水压力，紊动粘性系数由K～ε紊流模型求解，非交错网格减化方程离散，降低插值运算。动量插值计算交界面流速，避免压力波动，由压力校正法求解压力—速度耦合问题。不平衡输沙方程离散后直接迭代求解。并建立底部切应力和泥沙床面交换计算方法。 (7)三维水流泥沙数值模型也采用S型弯道三维水流运动、床面泥沙单纯冲刷上扬和单纯淤积水槽的试验实测资料进行验证，结果合理、有效。 (8)天然三维水流泥沙简化数值模型，成功地模拟南京某河段水流运动和多分汊河道水沙计算，结果可靠并满足精度。更多还原

【Abstract】 1. In this paper, a brief introduction of hydrodynamic, sediment transport model and its application in engineering projects are reported.2. The equations are derived using a tensor analysis of two-phase flow, and the background of basic equations and parameters in the numerical model are discussed.3. Based on Poission equation conversion, generated methods of curvilinear grids are presented.4. 2-D flow and sediment transport model with non-staggered curvilinear grids is presented. To prevent the pressure oscillation on non-staggered grids, an interpolation method called momentum interpolation is presented to evaluated the cell-face velocities. The contravariant velocity fluxes are used as the dependent variables in the paper. The discretization equations were sieved using the SIMPLE, SIMPLEC and SIMPLER algorithms. Suspended and bed load transport were simulated with a non-equilibrium method. The source treatments in sediment transport equations, suspended load carrying capacity of the non-uniform material and exchange of size-distribution of the bed material are presented.5. In order to verify and test the applicability of the model, "S" type open channel flow is simulated with this model, the agreement with measurements was generally good. The mathematical model was applied to serve the engineering projects. The different water levels and flow discharges in Nanjing river reach are calculated, bed scour and sedimentation in this engineering reach during one hydrologic year are verified . All results are in good agreement withfield measurements. River hydrodynamic conditions and bed scour and sedimentation were predicted using the numerical model under engineering design conditions.6. A 3-D flow and sediment model in curvilinear collocated grid is developed from 2-D model. In the horizontal x-y-plane, a boundary-fitted curvilinear co-ordinate system is adopted, while in the vertical direction, a o-co-ordinate transformation is used to represent free surface and bed topography. The total pressure is subdivided into the hydrostatic and residual hydrodynamic components. K-e turbulent flows model, non-staggered curvilinear grids, momentum interpolation, SIMPLEC and SIMPLER algorithms are used to solve the basic equations. Non-equilibrium sediment transport is applied in the model. The treatments of bed shear stress and the equilibrium concentration are presented.7. 3-D flow in "S" type channel bend is simulated. The suspended load model was tested for open channel flow situation under erosion and deposition, separately. The results for the numerical model are tested against available data. Good agreement is obtained.8. A simplified 3-D natural river flow and sediment transport model is developed based on hydrostatic pressure distribution. The model has been applied to investigate the 3-D flow and suspended-load transport in Nanjing river reach with two branches. Computed results show that the 3D distribution of flow velocities and suspended concentrations in two branches are in good agreement with field measurements. It shows that the simplified model is applicable and reliable.更多还原